This commit makes BKE_image_acquire_ibuf referencing result, which means once
some area requested for image buffer, it'll be guaranteed this buffer wouldn't
be freed by image signal.
To de-reference buffer BKE_image_release_ibuf should now always be used.
To make referencing working correct we can not rely on result of
image_get_ibuf_threadsafe called outside from thread lock. This is so because
we need to guarantee getting image buffer from list of loaded buffers and it's
referencing happens atomic. Without lock here it is possible that between call
of image_get_ibuf_threadsafe and referencing the buffer IMA_SIGNAL_FREE would
be called. Image signal handling too is blocking now to prevent such a
situation.
Threads are locking by spinlock, which are faster than mutexes. There were some
slowdown reports in the past about render slowdown when using OSX on Xeon CPU.
It shouldn't happen with spin locks, but more tests on different hardware would
be really welcome. So far can not see speed regressions on own computers.
This commit also removes BKE_image_get_ibuf, because it was not so intuitive
when get_ibuf and acquire_ibuf should be used.
Thanks to Ton and Brecht for discussion/review :)
- Make mask
- assign to image editor
- disable fake user
This would make the image space reference a zero user mask datablock which wouldn't be saved.
solve the bug by making mask and image assignments check the real usercount of the ID block (not taking into account fake user).
- use Alt to modify all mask feather at once while dragging.
- copying a multi-user mask from the interface works now.
- show masks when UV editing isnt used, rather then checking editmode (would give some odd/annoying image space header).
- add a fake mask user by default.
- moving points with LMB drag no longer selects them.
